For other calls, R uses the default method instead of the one for lavaan, leading to other errors:
Error: $ operator not defined for this S4 class
Here too, selectMethod() seems to indicate that everything is fine.
As I mentioned, this happens in “some” R sessions, but I haven’t been able no narrow down what distinguishes “bad” from “good” sessions (where the problem does not occur). I’ve tried starting with a new session with just package lavaan loaded (where it works) and then one by one loading the same packages I have loaded in a bad session, but I can’t reproduce the error in the new session.